CHICAGO, April 20 (Xinhua) -- Researchers at the Institute for Molecular Engineering at the University of Chicago have developed a new way to target immunotherapies and deliver them directly to tumors, helping to both reduce side effects and make the therapies more effective in treating cancer.

According to a news release posted on the website of the university on Friday, while other researchers have developed systems that target a specific tumor protein or the tumor's DNA, the University of Chicago researchers take a unique approach: targeting collagen.

To deliver the drugs to the tumor, the researchers bound the two therapies, one called checkpoint inhibitors (CPIs) and another interleukin (IL)-2, to a blood protein that circulates and binds to collagen in areas of vascular injury, causing blood to coagulate and seal up the injury. Because a tumor is filled with leaky blood vessels, the protein would see those vessels as vascular injury and bind to them, delivering the therapies directly into the tumor's collagen.

The IV-administered therapy also has the advantage of finding and treating metastatic tumors throughout the body that may be unknown to the patient.

As initial results, the researchers found that a combination of CPI and IL-2 administered via their technique eradicated breast tumors in 9 of 13 animal models. In contrast, when the researchers administered the drugs without the collagen-seeking protein, only one breast tumor was eradicated.

The technique also slowed the growth of melanoma and colon tumors and reduced liver and lung toxicity from the drugs, which would translate into fewer side effects for patients.

In the next step, the researchers will work to improve efficacy even more by exploring the technique with other molecules, including molecules that were developed for cancer therapies but deemed too toxic for patients. The ultimate goal is to begin testing these combined therapies in clinical trials, ideally within three years.

"This therapy could be relevant to many solid tumors," said Jeffrey Hubbell, a professor in tissue engineering who co-authored the research. "We want to move this forward to clinical trials and perhaps help patients who have not responded to these therapies before."

The study was published early this month in the journal Science Translational Medicine.